Explanation:
This artistic image
is actually the signature of
a supermassive black hole in the center of distant galaxy M84
- based on data recently recorded by
Hubble's new Space Telescope Imaging Spectrograph
(STIS).
Very near black holes
the force of gravity is so strong that even light
can not escape ...
but the presence of a black hole can also be
revealed by watching matter fall into it.
In fact, material spiraling into a black hole would find its speed increasing
at a drastic rate.
These extreme velocity increases provide a "signature" of the
black hole's presence.
STIS relies onthe Doppler effect to measure gas velocity rapidly increasing to
nearly 240 miles per second within 26 light years of
the center of M84, a galaxy in the Virgo Cluster
about 50 million light years away.
The STIS data show
that radiation from approaching gas, shifted to blue wavelengths
left of the centerline, is suddenly redshifted
to the right of center indicating a rapidly rotating disk of material
near the galactic nucleus.
The resulting sharp S-shape is effectively the signature of a
black hole estimated to contain at least 300 million solar masses.
Do all galaxies have central black holes?